Alloy steel containing nickel, silicon, and copper



Patented Apr. 7, 1931 UNITED STATES 'ATENT OFFICE PERCY A. E. ARMSTRONG, OF NEW YORK, AND RALPH 1. DE VRIES, F MENANDS, NEW YORK, ASSIGNORS TO LUDLUM STEEL COMPANY, OF WATERVLIET, NEW YORK, A

CORPORATION OF NEW JERSEY ALLOY STEEL CONTAINING NICKEL, SILICON, AND COPPER No Drawing. Original application filed. January 7, 1921, Serial No. 435,706. Divided and this application filed July 5, 1928. Serial No. 290,692.

This application is a division of our copending application Serial No. 435,700, filed January 7, 1921.

Our invention relates to an alloy steel containing nickel, silicon and copper, and which is of stable surface character and in particular is resistant to acid corrosion and to oxidation at visible heats.

Addition of silicon to iron gives increased stable surface properties roughly propor tional to the silicon content, but as the silicon alloyed with iron is increased brittleness of the alloy is increased.

With incorporation of nickel with silicon and iron, the proportion of silicon can be very considerably increased and a highly stable surface material obtained and at the same time the brittleness which would be present without the nickle is avoided or decreased, and tough material obtained,that is, material which can be bent to some extent without breaking.

Copper incorporated with the other constituents of the alloy gives increasedstable surface properties, and has the advantage that its addition does not require the reduction of silicon to obtain material which is tough.

The beneficial effects of the alloying constituents are not obtained to a marked degree when the nickel is under about the silicon under about 2% and the copper under about .5%. With 2% or more of copper its beneficial effects are readily apparent. The carbon may be as low as practicable and the lower limit is about .05%, but ordinarilyneed not be under about .15%.

Nickel is preferably over 20%, but should preferably not exceed about 40% for reasons stated below in connection with silicon. From 2% to 5% of silicon gives best results for parts to be mechanically hot worked, but where the nickel is low, silicon up to can be used, and if avoidance of brittleness is not important, the silicon may be increased to as much as or 16%, but such material will be brittle, particularly if the nickel is low. For any given proportion of nickel, the temperatures which can be withstood without substantial oxidation or scaling rise with increase of the silicon content. The silicon that can be incorporated and tough material obtained increases with increase of nickel up to about 20% of nickel; from about 20% to of nickel there is little change in the proportion of silicon that can be used, and above about 40% of nickel the proportion of silicon can no longer be increased, and in order toget desirably tough material silicon should be decreased somewhat as nickel is increased.

The carbon should not exceed a maximum of about 1.5%, and for mechanically hot worked articles may advantageously be kept under .6%.

, In case of acid resisting articles in the cast condition, the copper content may be increased to about 15%, with improvement of the acid resisting qualities, and a good example of such material was of the following analysis: Carbon 30% silicon 4.32%; nickel 37.86%; copper 11.68%, and the principal portion of the remainder iron. I

We claim:

1. An article resistant to corrosion and to hot oxidation, made from alloy steel containing, as essential constituents, nickel about 5-% l0%, silicon about 2%7%, copper about .5%15'%, carbon about .05%-1.5%, balance substantially all iron.

2. An article resistant to corrosion and to hot oxidation, made from alloy steel con taining, as essential constituents, nickel about 20%40%, silicon about 2%7%, copperabout2%-10%, carbon under .6=%.

3. An article resistant to corrosion and to hot oxidation, inade from alloy steel containing, as essential constituents, nickel about 37%, silicon about 4%, copper about 12%. carbon about 3%. g

In testimony whereof, we have signed our names hereto.

PERCY A. E. ARMSTRONG. RALPH P. DE VRIES. 

